Modified Compression Field Theory Research Articles

Vertical shear capacity of steel–normal concrete-UHPC composite slabs with steel ribs in the cantilever

UHPC is utilized to enhance flexural performance of tensile zone of composite slabs, which will enable reducing slab height. The vertical shear resistance of composite slabs in the cantilever might become insufficient with the reduction of slab height. In the paper, the vertical shear performance of steel-normal concrete-UHPC composite slabs in the cantilever is investigated based on five composite slabs tests, numerical simulation, and theoretical analysis. The results indicate that UHPC layer changes the failure mode of steel concrete composite slabs. The bearing capacity and ductility of composite slabs are effectively enhanced with the application of UHPC. The addition of a 10 cm UHPC layer makes the bearing capacity of composite slabs increase by 69.97%. And the reinforcement ratio of UHPC layer and the type of steel ribs exert a significant influence on the shear resistance. Additionally, an analytical model derived from modified compression field theory can well predict vertical shear bearing capacities of composite slabs in the cantilever.

Experimental and numerical analysis on shear capacity of steel-reinforced geopolymer concrete beams with different shear span ratios

PurposeThe purpose of this study is to use the corrected stress field theory to derive the shear capacity of geopolymer concrete beams (GPC) and consider the shear-span ratio as a major factor affecting the shear capacity. This research aims to provide guidance for studying the shear capacity of GPC and to observe how the failure modes of beams change with the variation of the shear-span ratio, thereby discovering underlying patterns.Design/methodology/approachThree test beams with shear span ratios of 1.5, 2.0 and 2.5 are investigated in this paper. For GPC beams with shear-span ratios of 1.5, 2.0 and 2.5, ultimate capacities are 337kN, 235kN and 195kN, respectively. Transitioning from 1.5 to 2.0 results in a 30% decrease in capacity, a reduction of 102kN. Moving from 2.0 to 2.5 sees a 17% decrease, with a loss of 40KN in capacity. A shear capacity formula, derived from modified compression field theory and considering concrete shear strength, stirrups and aggregate interlocking force, was validated through finite element modeling. Additionally, models with shear ratios of 1 and 3 were created to observe crack propagation patterns.FindingsFor GPC beams with shear-span ratios of 1.5, 2.0 and 2.5, ultimate capacities of 337KN, 235KN and 195KN are achieved, respectively. A reduction in capacity of 102KN occurs when transitioning from 1.5 to 2.0 and a decrease of 40KN is observed when moving from 2.0 to 2.5. The average test-to-theory ratio, at 1.015 with a variance of 0.001, demonstrates strong agreement. ABAQUS models beams with ratios ranging from 1.0 to 3.0, revealing crack trends indicative of reduced crack angles with higher ratios. The failure mode observed in the models aligns with experimental results.Originality/valueThis article provides a reference for the shear bearing capacity formula of geopolymer reinforced concrete (GRC) beams, addressing the limited research in this area. Additionally, an exponential model incorporating the shear-span ratio as a variable was employed to calculate the shear capacity, based on previous studies. Moreover, the analysis of shear capacity results integrated literature from prior research. By fitting previous experimental data to the proposed formula, the accuracy of this study's derived formula was further validated, with theoretical values aligning well with experimental results. Additionally, guidance is offered for utilizing ABAQUS in simulating the failure process of GRC beams.

A numerical critical shear crack model and its application to post‐peak behavior assessment of RC and SFRC beams

AbstractIn this paper, a numerical critical shear crack model, in which the shear‐flexural coupling effect is considered and the full process of stress and strain is captured, is proposed to evaluate the post‐peak behavior of reinforced concrete (RC) and steel fiber reinforced concrete (SFRC) beams. The shape of critical shear crack is identified by combining the modified compression field theory considering the bridge effect of steel fibers and the section analysis method. Based on the shape of critical shear crack, the shear capacity of beam members is provided by the shear tension zone and the shear compression zone. The shear capacity of the shear tension zone is calculated by the modified compression field theory and that of the shear compression zone is determined by multiaxial strength criterion of concrete. The vertical displacements caused by the flexure deformation and shear deformation are deduced by the moment area method and integration of shear strain. To verify the proposed numerical approach, a test database of 486 RC beams and 313 SFRC beams was established to predict the shear strength, and the force‐displacement relationships of twelve beam members are used to validate the feasibility for full process analysis. The stochastic analysis of beams with different failure modes is conducted via GF‐discrepancy‐based point selection method and probability density evolution method. The limitation between different failure modes is defined according to the degradation percent of shear capacity and it is taken as threshold value of failure domain, and the failure probability analysis indicates that the designed flexure beam member suffered severe degradation of shear capacity, resulting in a significant decline in safety probability.

Effect of steel fiber orientation on punching shear resistance of steel fiber reinforced cementitious composites round slabs

The slab-column structure is commonly used in civil engineering. At the slab-column joints, the load from the slab is transmitted to the column. In the extreme state, punching shear failure may occur at the joints, and the failure is brittle without warning. When the punching shear failure occurs at the joint of round slab and column, usually the cracking is a conical shape because the direction of tensile stress caused by punching shear is generally radial. By incorporating steel fibers into cementitious composites round slabs, the steel fibers can bridge the conical surface, and therefore enhance the punching shear resistance of round slabs. If the steel fibers in the round slab are dispersed in the direction conducive to the punching shear resistance, the steel fibers can take full effect of strengthening and toughening, thus improving the punching shear resistance of the slab. So, the purpose of this investigation is to improve the punching shear resistance of steel fiber reinforced cementitious composite slabs by maximizing the reinforcement of steel fibers on the composites. Firstly, a model of punching shear resistance of steel fiber reinforced cementitious composite round slabs was derived based on the Modified Compression Field Theory with consideration of the orientation of steel fibers. According to the model, the slab with radial distribution of steel fibers around the punching shear area shows the highest punching shear resistance. Secondly, the approach of radially aligning steel fibers in the slab around the punching area by magnetic driving is proposed using a self-developed magnetic device. And, radially dispersed steel fiber reinforced cementitious composites (JD-SFRC) round slabs were prepared. Thirdly, the punching shear resistance of JD-SFRC round slabs, as well as unidirectionally aligned (1D), two-dimensionally aligned (2D), and randomly distributed (RD) steel fiber reinforced cementitious composites round slabs were tested. At last, the effect of the orientation of steel fibers on the punching shear resistance and failure characteristics of the round slabs were analyzed by comparing the results from tests and the model. Meanwhile, the effect of the volume fraction of steel fibers on the punching shear resistance of the slab was examined. The results show that, When the volume fraction of steel fiber is 1.0 %, compared with RD-SFRC round slabs, the ultimate shear resistance of 1D-SFRC, 2D-SFRC and JD-SFRC round slabs is increased by 14 %, 15 %, and 24 %, respectively.

Shear Bearing Capacity Prediction of Steel-Fiber-Reinforced High-Strength Concrete Corbels on Modified Compression Field Theory

In order to analyze the shear mechanism of the steel-fiber high-strength concrete corbels, a calculation model for the shear bearing capacity of steel-fiber-reinforced high-strength concrete corbels was proposed based on the modified compression field theory. Considering the existence of residual tensile stress in steel-fiber-reinforced concrete at crack locations, the cracked steel-fiber-reinforced concrete was treated as a continuous material. The constitutive relation of cracked steel-fiber-reinforced concrete and the local stress equilibrium equation were modified. It was compared with the results of 34 steel-fiber high-strength concrete corbels, including those in this paper. The predicted results were compared with the experimental values and the predictions of the Fattuhi model, Campione model, and Russo model to validate the rationality of the proposed model. The results revealed that the mean value between the experimental values and the predicted results of the proposed model is 1.104, with a variance of 0.003, showing good agreement. The proposed model can accurately predict the shear bearing capacity of steel-fiber-reinforced high-strength concrete corbels.

Design of UHPC prestressed girders for shear

AbstractBreakthrough technology of ultra‐high‐performance concrete (UHPC) introduced in the 1990s exhibits several exceptional mechanical properties that are advantageous in elements of bridge applications. Extensive research has aimed to industrialize UHPC and develop design models. This paper investigates several design models for shear, including a unified approach with that of conventional concrete based on the modified compression field theory (MCFT). An experimental database of UHPC prestressed concrete girders subjected to shear failure is compiled to evaluate model accuracy and a reliability study is conducted to establish appropriate safety factors. The analysis demonstrates that the proposed MCFT‐based model aligns well with experimental results, exhibiting a suitable level of conservatism for design. A reliability assessment of a typical prestressed girder designed according to Canadian Standards Association building and bridge loadings is performed, resulting in a structural reliability evaluation against a target reliability index. The study recommends specific strength reduction and safety factors for design approaches using UHPC.

A novel design model for predicting the shear resistance of reinforced concrete beams strengthened with EBR-CFRP systems

Shear resistance prediction of reinforced concrete (RC) beams strengthened with externally bonded reinforcements (EBR) is a challenging task due to the complex nature of shear resisting mechanisms and their intricate interaction. Existing design models often overlook these dependencies, leading to significant variations in prediction accuracy. In this paper, a design model is proposed by integrating the most relevant shear resisting mechanisms based on the evidence demonstrated by a large database of experimental results from RC beams shear strengthened with wet layup carbon fibre reinforced (CFRP) sheets applied according to the EBR technique. The developed approach integrates the simplified modified compression field theory (SMCFT) with a regression-based model. A global sensitivity analysis was conducted according to which closed form equations were derived to obtain the tensile stress factor in cracked concrete and the inclination angle of the critical diagonal crack. A reliability analysis is carried out, and resistance reduction factors are achieved for different levels of reliability index. The database, composed of 284 RC beams shear strengthened with EBR-CFRP technique, is utilized to validate the proposed model, and compare its performance against some well-established existing design models. The results show that the proposed model, with an adequate framework for its use on design practice, outperforms the other considered models.

SAFETY ASSESSMENT OF CONTINUOUS CONCRETE GIRDER BRIDGES SUBJECTED TO RANDOM TRAFFIC LOADS CONSIDERING FLEXURAL-SHEAR COUPLED FAILURE

Bridges generally perform complicated mechanical behaviors under external loads, such as flexural-shear coupling, compression-bending coupling, and flexural-shear-torsion coupling. In the context of deterministic design approaches such as design codes, these complicated coupled issues are generally simplified to the safety verification of bridge components under a single mechanical state (i.e. flexural, shear, torsion). At present, the rapid development of sensor and information technologies makes it possible to collect the external loads acted on bridges and understand bridge performance under these stochastic external loads. In this manner, the reliability-based full probabilistic approach could be applied to investigate the performance of bridges over their lifetime. However, the current bridge reliability assessment incorporating realistic traffic load measurements mainly focuses on the analysis of bridge components under a single mechanical state. In this paper, a reliability-based probabilistic analytical framework of the flexural-shear performance of girder bridges under random traffic loading is established. The flexural-shear coupled failure path of bridge girders under random traffic loading is characterized for the first time, where the bivariate extreme value theory is incorporated to develop the extreme value distribution of combined flexural and shear load effects. The modified compression field theory recommended by AASHTO is employed to establish the coupled flexural-shear coupling resistances. Finally, the reliability of the flexural-shear performance of bridge girders is evaluated by solving the multivariate ultimate limit state equation. The proposed analytical framework is applied to a realistic bridge. The results show that the reliability index of the flexural-shear coupling evaluation is lower than that of the flexural or shear evaluation, which highlights the importance of the flexural-shear performance checking in the reliability assessment of bridges under random traffic loading. The proposed analytical framework could be further applied to the probabilistic assessment of bridge components subjected to combined loading mechanisms under random loadings.

MODELING THE BENDING BEHAVIOR OF STEEL FIBER-REINFORCED CONCRETE BEAMS

In this study, modeling of the bending behavior of large-scale steel fiber-reinforced concrete beams (SFRC) was investigated using the Modified Compression Field Theory (MCFT) based non-linear finite element (NLFE) method and an analytical method. The two analysis methods included different modeling approaches for the contribution of steel fibers to the tensile strength of reinforced concrete. In the first approach, the residual tensile strength of fibrous concrete was related to the crack width and adopted into the MCTF-based NLFE method. However, the residual tensile strength was free from the crack width in the second approach, which was employed in the analytical method. The capabilities of the mentioned analysis methods were investigated on an experimental study selected from the literature. The experimental study included the four-point bending tests of five four-meter-long simply supported SFRC beams having various ratios of longitudinal reinforcement and fiber content. Results revealed that the MCTF-based NLFE method performed superior in representing the large-scale member responses (such as load-carrying capacity, crack profiles, and flexural stiffness) for the selected loading and boundary conditions while the simplified analytical tool was found to be always conservative in the determination of strength regardless of conventional reinforcement and fiber ratio. However, the rate of error was apparently proven to be highly dependent on the tensile reinforcement ratio.

Exploring the shear performance and predictive shear capacity of corroded RC columns utilizing the modified compression-field theory: An investigative study

Corrosion damage substantially weakens the shear strength of reinforced concrete (RC) structures, severely compromising their seismic resistance. Therefore, developing an accurate constitutive model is imperative to investigate the impact of corrosion damage on the shear resistance of RC structures. This study presents a corroded RC shear constitutive model based on the modified compression-field theory (MCFT). To capture the flexural, shear, and slip responses of corroded RC columns accurately, a nonlinear analysis model based on OpenSees is proposed. Comparing the results from four sets of quasi-static tests reveals that the proposed constitutive model and analysis framework can well simulate the seismic performance of corroded RC columns. Based on the comparative analysis, the influence of corrosion-induced damage, reinforcement ratio, and axial load on the shear performance of RC columns is discussed. The investigation findings reveal that high corrosion levels and low reinforcement ratios remarkably weaken the shear strength of RC columns. Additionally, high axial load levels accelerate the rate of post peak shear stress degradation. Moreover, this study proposes a method for estimating the shear strength of corroded RC columns based on the MCFT. The presented approach provides a solid foundation for evaluating the shear and seismic performance of existing RC structures.

Shear behavior of RC beams strengthened with high-strength steel strand mesh reinforced ECC: Shear capacity, cracking and deformation

An experimental and theoretical study on the shear behavior of reinforced concrete (RC) beams strengthened with high-strength steel strand mesh reinforced engineered cementitious composites (HSSM-ECC) was reported in this paper. Four-point bending test was performed on a total of ten strengthened beams and three referential beams, considering the test variables of the shear-span ratio, the reinforcement ratio and diameter of HSSM, the water-binder ratio and thickness of ECC layer, and strengthening configuration. Test results showed that the shear performance of the strengthened beams was significantly enhanced, and the multi-cracking pattern was observed in the strengthened beams, which effectively reduced the crack width and the brittleness of RC beams in shear. In addition, the effect mechanism of test variables on the shear behavior of strengthened beams was discussed in detail. Finally, considering the effects of dowel action of longitudinal rebars and flexural-shear combination, a comprehensive analysis model for predicting shear capacity, shear deformation, and maximum shear crack width based on modified compression field theory was proposed, which was found to be acceptable for more accurate prediction of shear capacity, shear deformation, and maximum shear crack width of strengthened beams by comparing with the test results and other existing models.

Numerical modelling of RC beams strengthened in shear using NSM FRP and cement based adhesives

Cement based adhesives (CBAs) are currently emerging as a suitable replacement for epoxy resins in the strengthening of reinforced concrete (RC) elements using near surface mounted (NSM) fiber reinforced polymers (FRP). However, large scale experimental testing on RC beams strengthened in shear using NSM FRP and CBA has been limited to date and there is currently an absence of strength prediction models and design guidelines to enable engineers to design and detail such strengthening systems. This paper expands the theoretical understanding of RC beams strengthened in shear using NSM FRP and CBA using 2D finite element modelling by developing an experimentally validated modelling approach. Later, parametric studies into five concrete strengths (25, 32, 40, 45 and 50 MPa) and three FRP spacings (100, 150 and 200 mm) were conducted to generate a database of results which can later be used to inform the development of design guidelines. Data on maximum FRP strains at failure were combined with existing shear strength prediction models based on the modified compression field theory (MCFT) and national design standards to propose a strength prediction modelling approach.

Development of multi-fiber approach finite element model for reinforced concrete beam using frp reinforcements under pure torsion

A finite element model using a multi-fiber approach is proposed in this paper for the analysis of reinforced concrete (RC) members using fiber-reinforced polymer (FRP) reinforcements, with a specific focus on the effect of pure torsion. The proposed model is formulated using a displacement-based approach and a kinematic assumption involving a two-node Timoshenko beam. The compatibility and equilibrium between concrete and FRP materials in the membrane elements are formulated based on a discretization of the cross-section into several areas following its stress state and the principle of the Modified Compression Field Theory. The nonlinear responses of RC elements with FRP bars can be predicted using an appropriate constitutive material law with internal equilibrium of transverse reinforcement and concrete. The pure torsional response is implemented using an enhanced formulation of concrete's tensile behavior, which is based on experimental tests on torsion and the characteristics of FRP materials. The good agreement between the numerical results and experimental data confirms the validity of the proposed model

Estimation of the shear capacity of decks in existing shorter reinforced concrete bridges

AbstractIt has been recognized that the shear capacity of old bridges can play a crucial/key role in evaluating their structural safety. Determination of the shear capacity of critical cross‐sections presents a much greater challenge than the assessment of their bending capacity.Due to abovementioned problems, the shear capacity of shorter reinforced concrete bridges with T‐beams has been evaluated with various models. Four different models were examined, the currently valid Eurocode 2, draft of the new version of Eurocode 2, the currently valid Eurocode 8‐3 and the model corresponding to modified compression field theory (MCFT). According to all the models, the capacity of deck of existing reinforced concrete bridge was calculated. This bridge was previously inspected and the actual amount and shape of the shear and bending reinforcement was determined.The results obtained with different models were compared and the typical parameters which influence the shear capacity were analyzed. The results in terms of shear capacity show that different models can give quite different results for the same bridge.

Predicting the shear behavior of reinforced concrete beams with Fe-Based shape memory alloy stirrups

Existing studies using Fe-based shape memory alloys (SMAs) for shear reinforcement have focused on strengthening aged structures. Studies on using Fe-SMAs as shear reinforcements for new structures have not been reported. Accordingly, this study performed experiments to evaluate the shear behavior of reinforced concrete (RC) beams with Fe-based SMA stirrups. Ten specimens were prepared for the experiments. The activation of the Fe-SMA stirrup, stirrup spacing, and shear span-to-depth ratio were considered as variables. The Fe-SMA stirrups were activated via electrical resistance heating. Activating the Fe-SMA stirrups applied compressive forces to the specimen, reduced the occurrence of diagonal shear cracks, and improved shear stiffness. However, it did not significantly affect the shear strength. The shear contribution of the Fe-SMA stirrup increased with an increase in the shear span-to-depth ratio and amount of shear reinforcement. In addition, the simulation results using the modified compression field theory (MCFT)-based section analysis model were consistent with the experiment results. Therefore, the model can predict the shear behavior of RC beams with Fe-SMA stirrups.

Prediction of the monotonic load–displacement curve of slender RC beams with corroded transverse and longitudinal reinforcements

AbstractThe present paper proposes a mechanical model for the prediction of the response of slender reinforced concrete beams with corroded transverse and longitudinal reinforcements. The proposed model is based on the Modified Compression Field Theory and is able to predict the load–displacement curve of members subjected to monotonic displacement‐controlled tests up to their peak load. The corrosion‐damage effects are considered by means of an effective width of the beam and by means of reduced values of both cross‐sectional area and strain capacity of steel bars. The accuracy of the model is evaluated by comparison with results of tests reported in the literature. Moreover, a simple relation is suggested for the estimate of the shear strength of reinforced concrete beams with low values of the effective geometric percentage of (corroded) stirrups.

Experimental and MCFT-Based Study on Steel Fiber-Reinforced Concrete Subjected to In-Plane Shear Forces

Testing of concrete panels subjected to pure in-plane shear loading is necessary to elucidate the shear behavior of concrete. However, available data for predicting the shear capacity and behavior of steel fiber-reinforced concrete are rather limited. This study aims to evaluate the shear capacity and behavior of fiber-reinforced concrete made of highly flowable strain hardening fiber-reinforced concrete (HF-SHFRC) experimentally and analytically, respectively, using a panel tester loaded under pure shear and modified compression field theory (MCFT). The test was conducted using a panel test machine at the University of Toronto. The test results of the HF-SHFRC demonstrated strain hardening behavior at tension after the first crack, as indicated by the increase in the shear stress after the first crack in the HF-SHFRC panel. An analysis procedure is proposed for predicting the shear strength of steel fiber-reinforced concrete (SFRC) based on experimental data of the SFRC panels to obtain reliable results. A comparison of results obtained from the proposed analysis procedure and experiments show that it accurately predicted the response of the HF-SHFRC. The proposed MCFT-based analysis procedure can provide valuable insight for understanding the behavior of the SFRC panels under shear loading.

Implementation of Modified Compression Field Theory to Simulate the Behavior of Fiber-Reinforced Polymer Shear-Strengthened Reinforced Concrete Beams under Monotonic Loading

The numerical modeling of structures is a widely preferable approach to investigate the structural behavior of RC beams since it delivers inexpensive predictions for confirming the required goals concurrently with reducing casting, testing time, and effort. Shear-strengthening of reinforced concrete (RC) beams using externally bonded (EB) fiber-reinforced polymers (FRPs) has attracted much attention due to the fact that the FRP strengthening technique has the ability to alter the distribution of stresses between the structural elements and increase the load-carrying capacity. A significant number of experimental studies have been carried out to test the monotonic behavior of FRP shear-strengthened RC beams. Conversely, limited numerical research has been performed to investigate such performance. The VecTor2 software is developed based on the modified compression field theory (MCFT) and is directed to examine the monotonic behavior of retrofitted specimens using fiber-reinforced polymer (FRP) composites. To the authors’ knowledge, the behavior of FRP shear-strengthened beams has not been explored in the literature using the MCFT modeling approach. The main objective of this study is to detect the software’s capability of predicting the experimental outcomes of FRP shear-strengthened RC beams. This research study is carried out in two stages. Initially, the numerical study involves the development of an accurate finite element model to simulate the control specimens. The quality of this model is assessed by comparing the numerical results with the experimental outcomes. In the second phase of the numerical study, the control beam model is modified to accommodate the presence of external FRP composites. The accuracy of this model is again measured by comparing its predictions with the experimental measurements. The goal of these phases is to ensure that the numerical model captures the actual behavior of the tested beams. Additionally, two distinctive modeling approaches are investigated to represent the behavior of FRP composites. The accuracy of the numerical models is verified through comparisons of numerical predictions to experimental results in terms of ultimate loading capacity, load–deflection relationships, and failure modes. It can be stated that the validated numerical model provides alternate means for evaluating the monotonic behavior of both strengthened and non-strengthened RC beams. The predicted results compare very well with the test results of the control specimens when discrete truss elements are employed for the FRP composites. Furthermore, the numerical model provides useful information on the crack patterns and failure modes.

Symbolic machine learning improved MCFT model for punching shear resistance of FRP-reinforced concrete slabs

Fiber reinforced polymer (FRP)-reinforced concrete slabs, an extension of reinforced concrete (RC) slabs leveraged for resisting environment corrosion, are susceptible to punching shear failure due to the lower elasticity modulus of FRP reinforcement. To estimate the punching shear resistance accurately, there are two types of models (e.g., white box and black-box models) proposed based on theoretical derivations and machine learning methods. However, these two types of models are considered as independent of each other. In this study, a hybrid model (e.g., grey-box model) derived from modified compression field theory (MCFT) is proposed by this paper, in which the performance is improved by a machine-learning-aided approach (genetic programming). In order to exploit the performance of machine learning, a database containing 154 experimental data is established and used for fitting the correction equations. Iterating the population containing 300 tree-based individuals in 300 times, a correction equation with simple format is obtained, which performs well in performance improvement of the basic model derived from MCFT. Herein, the influential factors involved in the correction equation comply with the sorting in order of the importance quantified by extreme gradient boosting (XGBoost) and shapley additive explanation (SHAP). Combining the correction equation with the basic model derived from MCFT, a symbolic regression MCFT (SR-MCFT) model is established, which performs better prediction performance than other five empirical models.

Strength prediction of a bottle-shaped strut for evaluating the shear capacity of reinforced concrete deep beam

For the analysis and design of reinforced concrete (RC) deep beams, the strut-and-tie model is typically employed to simulate the flow of stresses. A bottle-shaped strut develops between the loading point and support, in which compressive stress spreads laterally and induces tensile strain in the transverse direction, which reduces the compressive strength of the strut significantly. Web reinforcements are provided in deep RC beams to prevent splitting of the diagonal strut due to the presence of these transverse strains. In this article, a simplified design procedure based on the strut-and-tie model (STM) is proposed for the evaluation of the shear capacity of deep beams with web reinforcement. The suggested model is based on modified compression field theory and considers the impact of shear reinforcement ratio, transverse tensile strain, post-cracking strength of concrete, and the actual dispersion of compressive stress based on strut geometry (aspect ratio) for strength prediction of bottle-shaped struts. The experimental results of RC panels and deep RC beams reported in the literature are used to validate the results of the suggested model. The findings demonstrate that the proposed STM evaluates the shear capacity of deep RC beams more precisely than capacities estimated by ACI 318-19, AASHTO LRDF, and Eurocode 2 (EC2). In addition, a comprehensive parametric study has been carried out to investigate the effect of various design parameters on the shear capacity of deep RC beams.